I struggled to get a solution to Record Collection but (after having a quick peek at the hints) get something which runs in my browser console and seems to make all the required changes to the record collection.

When I ‘Run the Tests’ I get an error:

updateRecords(...)[5439].tracks.pop is not a function

I do not even use .pop in my code so this is confusing me.

My solution to the problem is to change the updateRecords() function to the the following: